【作者】 杨宏杰；

【导师】 冯凤琴；

【作者基本信息】 浙江大学 ， 食品科学与工程， 2004， 硕士

【摘要】 本论文研究月桂酸单甘酯(简称GML)的合成与提纯，目的是得到单甘酯含量90％以上的产品。并在此过程中，建立了月桂酸单甘脂的定量方法。 本文通过比较，选择气相色谱法来测定产品中月桂酸单甘脂的含量。气相色谱法采用色谱柱为OV—17玻璃填充柱(1.5m长，3mm内径，岛津公司)，FID检测器。进样室温度320℃，检测器温度为330℃。柱子采用程序升温，分三个阶段：120—240℃，每分钟升温10℃；240—300℃，每分钟升温15℃；300℃恒温停留3分钟。载气为氮气，流速为75ml／分钟。六甲基二硅胺烷(HMDS)和三甲基氯硅烷(TMCS)作为衍生剂，在吡啶中把月桂酸单甘酯合成粗品中的各种组分硅烷化，并以十四酸作为内标物，用内标法进行定量。月桂酸单甘酯的线性范围是1.11～11.11mg／ml，最低检出限是0.063mg／ml。 通过对脂化温度、甘油和月桂酸的摩尔比、催化剂的种类和用量等因素进行试验，得出直接脂化反应的最佳条件是：温度180℃，甘油与月桂酸的摩尔比2：1，对甲苯磺酸的用量0.15％。 由于GML是热敏性难分离物质，所以需要采用分子蒸馏(Molecular Distillation)提取高纯度的GML产品。本文从空气残压，蒸馏温度，冷凝面温度等几个方面着手，结合分子平均自由程理论，确定了GML粗产品的分子蒸馏工艺：首先在蒸馏温度90℃，冷凝面温度60℃，空气残压5Pa条件下蒸出月桂酸和甘油；然后把蒸余部分在蒸馏温度100℃，冷凝面温度70℃，空气残压0.1Pa条件下蒸馏，得到的馏分就是纯度不少于90％的GML产品。 并进行了产品的中试，效果比较理想，得到的产品中单酯含量为90.36％，月桂酸单甘酯的回收率为81.32％。更多还原

【Abstract】 The objective of this study was to produce high-purity(≥90%) Glycerol Monolaurate (GML) through synthesis and purification.After comparing with other methods, GC analysis was choosed to determine GML in products. HMDS and TMCS were used as derivatization agent in GC analysis, while pyridine was used as solvent and catalyst. After derivatization, separation of samples containing GML could be achieved through a OV-17 glass column. Operating condition as follows: FID as detector, injection temperature at 320 ℃ ,detection temperature at 330℃ ,flow rate of N2 at 75ml/min and temperature program adopted. Temperature program was divided into three stages: first ascending from 120 to 240℃ at 10℃ /min; then ascending from 240 to 300℃ at 15℃ /min; And lastly staying at 300℃ for 3 minutes. The quantitative analysis of GML was carried out by internal standard method, with Tetradecanoic acid as internal standard. In this method, Linear range was 1.11-11.1 Img/ml and detection limit is 0.063mg/ml.After study on some important factors such as mole ratio of glycerol to Laurie acid, synthesis temperature and catalyst, the optimum condition of synthesis was determined. That was: synthesis temperature was 80℃ , mole ratio was 2:1, and 0.15% P-Toluene Sulphonic acid was served as catalyst.Because GML was thermal unstable and hard to distill, Molecular Distillation was used to purify crude product containing GML. In this paper, to determine the technique about Molecular Distillation of Glycerol Monolaurate, operating pressure, distillation temperature, condensation temperature and flow rate of distillation was studied in accordance with Mean Free Path Theory. The technique was made up of two stages: first glycerol and Laurie acid were distilled with operating pressure at 5Pa, distillation temperature at 90℃ , and condensation temperature at 60℃ ; then GML was distilled with operating pressure at 0.1 Pa, distillation temperature at 100℃ , and condensation temperature at 70℃ . high-purity(≥90%) GML was achieved by this technique.And a pilot-plant test was conducted. The result was encouraging: the content of GML was 90.36% and the recovery of GML was 81.32%.更多还原